追加到Scala环境变量

Question

我找不到将附加到环境变量的示例。例如，下面的代码完全取代了PATH。可能有人帮助我追加，直接或通过展示我如何访问当前PATH，这样我就可以修改本身并通过全改性价值的Process

val out2 = Process("env", None, "PATH" -> "/usr/local/bin") 

Answer 1

有：

scala> util.Properties.envOrNone("PATH") 
res0: Option[String] = Some(/home/apm/go1.1/go/bin:/home/apm/go/bin:/home/apm/bin:/usr/lib/lightdm/lightdm:/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/games) 

那就是：

scala> util.Properties.envOrSome("PATH", Some("")) map (p => s"$p${new sys.SystemProperties()("path.separator")}/tmp") get 
warning: there was one feature warning; re-run with -feature for details 
res5: String = /home/apm/go1.1/go/bin:/home/apm/go/bin:/home/apm/bin:/usr/lib/lightdm/lightdm:/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/games:/tmp 

我只注意到我的道路已经过时。

编辑的成语：

scala> def appendToEnv(key: String, value: String) = util.Properties.envOrNone(key) match { 
    | case Some(v) if v.nonEmpty => s"$v${System getProperty "path.separator"}$value" 
    | case _ => value 
    | } 
appendToEnv: (key: String, value: String)String 

scala> appendToEnv("PATH", "/opt") 
res0: String = /home/apm/go1.1/go/bin:/home/apm/go/bin:/home/apm/bin:/usr/lib/lightdm/lightdm:/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/games:/opt 

scala> appendToEnv("UNPATH", "/opt") 
res1: String = /opt